Alterations in Cell Signaling and Cytotoxicity

Abstract

Cells communicate by means of chemical signaling such as that mediated by hormones, neurotransmitters, cytokines and by intercellular contacts achieved through gap junctions and other transmembrane proteins. During the last few years, it has become increasingly clear that environmental toxicants can interact with cellular signal transduction pathways, affecting the ability of the cells to adequately respond to variety of signals. The alteration of cellular responses to hormone and growth factors, as well as the inability to deliver appropriate signals to other cells, will result in the lack of trophic stimulation. In addition, it may also determine a progressive alteration in cell plasticity and modify the program for differentiation. Ultimately, toxicant-induced disturbances in cell signaling can lead to the inappropriate activation or suppression of the cell death program, apoptosis. Thus, exposure to chemicals rather than causing rapid cell killing with loss of function, may eventually induce subtle alterations in normal signaling, resulting in long-lasting pathological effects. The potential targets on the cell signaling pathways are numerous and disparate, as is their sensitivity to toxicant-induced modifications. The purpose of this chapter is confined to reviewing the issues discussed at the symposium “Alterations in Cell Signaling and Cytotoxicity” given at the XIIth International Congress of Pharmacology, 1994.KeywordsFetal Alcohol SyndromeMuscarinic AgonistRINm5F CellConnexin ProteinDevelopmental NeurotoxicityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.